This invention relates generally to frozen food trays and more particularly to a new and novel improved ovenable paperboard carton of the type having a lid attached which may be used in a microwave and a conventional oven. This versatility of use in either type oven enables the packager of frozen food to eliminate the need for two types of frozen food packages. Use of the new and novel paperboard carton herein disclosed would appeal to the housewife who uses the conventional type oven as well as the housewife who uses the more recent microwave oven.
Many of the prior art frozen food packages are formed from aluminum which, it is believed, cannot be used in today's modern microwave ovens without damaging the radiation element. These aluminum packages are not only restricted to use in conventional ovens but are generally more costly to manufacture than a paperboard carton of the type herein disclosed by the applicant's invention.
Many prior art aluminum type frozen food packages required an inner container in which the frozen food was placed and also an outer paperboard container which not only protected the aluminum container from damage during shipping and storage but which also provided a means for printing the advertising of the packager. Oftentimes the outer paperboard container was not printed itself but had an additional paper layer on which the advertising was printed. Not only did this add to the expense of the package, but it was necessary that the housewife remove the outer paperboard container and additional paper layer before reheating the frozen food contained within the aluminum inner container.
The applicants' new and novel ovenable paperboard carton, having a one-piece lid, is constructed so that it not only provides the structural stability required to protect the contents of the package, but it may also have printed on its exterior portion the packager's advertising thus eliminating the need for an outer package and resulting in a greater cost savings to the packager and the ultimate consumer.
Another problem encountered in today's mechanized world is the speed of packaging. The folding and gluing of the applicant's new and novel ovenable paperboard carton is well suited to today's high speed packaging lines and the elimination of the outer package also increases the speed of packaging and results in even further savings to the packager of frozen food and the ultimate consumer.
Other problems facing the food packaging industry are those of securing a leakproof tray. Many prior art trays were constructed in such a manner that they were leakproof to the extent that contents contained within the tray could not leak to the outside of the tray, but seepage could occur between the interior and exterior walls of the tray. The problem is particularly prevalent in the packaging of foods containing sauces, gravies and the like. Examples of prior art trays of this type are shown in U.S. Pat. No. 2,531,255 issued to J. D. Clarke on Nov. 21, 1950, and U.S. Pat. No. 2,628,012 issued to M. Goldsholl on Feb. 10, 1953.
Other prior art packages are cited herein to show the state of the art and are shown in the U.S. Pat. No. 3,298,505, issued to E. E. Stephenson on Jan. 17, 1967; the U.S. Pat. No. 3,606,078, issued to F. L. Phillips, Jr. on Sept. 20, 1971; the U.S. Pat. No. 3,572,576, issued to Thomas W. Foster on Mar. 30, 1971; the U.S. Pat. No. 3,876,132, issued to Morris W. Kuckenbecker on Apr. 8, 1975; the U.S. Pat. No. 2,071,949, issued to S. Reich on Feb. 23, 1937; the U.S. Pat. No. 3,082,928, issued to R. F. Schenk on Mar. 26, 1963; the U.S. Pat. No. 3,905,543, issued to Arthur E. Randles on Sept. 16, 1975 and the U.S. Pat. No. 3,863,832, issued to Robert L. Gordon et al. on Feb. 4, 1975.
An earlier embodiment of a frozen food tray of the type for use in various ovens in shown in the U.S. Pat. No. 4,003,514, issued to Earl J. Graser on Jan. 18, 1977, and in the prosecution of that case in the U.S. Patent Office there was disclosed other prior art packages which are cited herein to show the further state of the art and were shown in the U.S. Pat. No. 2,447,243, issued to W. G. Freel et al. on Aug. 17, 1978; the U.S. Pat. No. 2,495,807, issued to K. T. Buttery on Jan. 31, 1950; the U.S. Pat. No. 3,301,391, issued to R. Guyer on Jan. 31, 1967; the U.S. Pat. No. 3,810,574, issued to Jeffrey M. Gardner on May 14, 1974 and the U.S. Pat. No. 3,917,155, issued to Robert B. Bemiss on Nov. 4, 1975.
In frozen food ovenable cartons, it is desirable to have rigidity built into the package so that the carton may be more easily removed from the oven. The reason for this is that the contents when frozen add to the rigidity but when thawed, the carton proper must be the sole means of support of the contents.
The poorly designed package will tend to twist when it is removed from the oven since the housewife usually grasps the package at one end. Accordingly, the entire weight of the thawed contents will tend to make the package distort in the housewife's hands. For a pictorial representation of this, reference should be made to FIG. 1A of a patent application filed simultaneously with this one by Earl J. Graser and Earl J. Killy and entitled "Ovenable Paperboard Carton". This application bears the U.S. Ser. No. 963,872 and filing date of Nov. 27, 1978 and is incorporated herein by reference.